by Paul Myerberg, USA TODAY Sports

by Paul Myerberg, USA TODAY Sports

The regular season, which is about to enter its final month, will end in one of three ways.

The first is the way we all dream about: with only two undefeated teams left standing. Whether it's Alabama and Oregon, Alabama and Notre Dame, Oregon and Kansas State or another permutation, having only two undefeated teams remaining come the end of the regular season sets up an argument-free national championship game.

The second is the way we've become accustomed to seeing: with three or more undefeated teams left standing. Based on how each team has fared and what each has left to go in November, it's not out of the realm of possibility that all four of the Tide, Ducks, Irish and Wildcats end the year at either 12-0 or 13-0.

The third way is the nightmare, worst-case scenario: five or six one-loss teams left juggling, bargaining and arguing for one of the two spots in the national championship game.

How close are we to this nightmare scenario? It's not too far-fetched a development to consider as both Oregon and Alabama prepare for their defining games of the regular season.

It would simply take a turnaround from USC, for one. The Trojans get Oregon on Saturday and Notre Dame three weeks later in the regular season finale. Matt Barkley, Marqise Lee and the rest of USC's offense can take down two undefeated teams by themselves.

Alabama heads into Death Valley to take on LSU on Saturday night ‚?? yes, Saturday night. The Tigers are 36-1 under Les Miles in home night games and have won 22 in a row in Baton Rouge, the nation's longest home winning streak. An LSU win over Alabama would lead to one wholly unexpected development: For the first time since the 2008 season, the SEC would not have a team finish the regular season undefeated.

Kansas State still has to face Oklahoma State and Texas, with the Cowboys coming to Manhattan on Saturday night. If the Wildcats lose at home to OSU or Texas (or at Baylor or TCU), all four of the teams currently jockeying for position along the top of the BCS standings will rejoin the rest of the pack.

Let's imagine the BCS kerfuffle that will ensue if all four teams lose in November. For one, would an undefeated Louisville team ‚?? if the Cardinals can get past Rutgers to end the year ‚?? be the de facto No. 1 team in the final rankings?

For argument's sake, let's say that Rutgers beats the Cardinals, leaving zero unbeaten teams in the entire FBS. (This doesn't count Ohio State, which is ineligible for postseason play.) How many one-loss BCS conference teams could be left with at least a slight case to be made for the championship game?

In the worst-case scenario, LSU would be 12-1, with a loss to Florida but with wins over Alabama and Georgia, the latter in the SEC championship game.

Alabama would be 11-1 with the loss to LSU; as in 2011, the Tide would be in the championship mix despite not winning their own conference, let alone their own division.

Kansas State would be 11-1 and the Big 12 champs. Notre Dame would be 11-1 with a loss to USC.

Oregon would be 12-1, having lost to USC in the regular season but having gained a measure of revenge in the Pac-12 championship game.

Florida State, which gets Florida in the season finale, would be 12-1. Clemson would be 11-1 with a competitive loss to FSU.

A number of two-loss teams would then be on the outside looking in, such as Florida, Georgia, Oregon State and Oklahoma, among others. One-loss teams like Rutgers (which lost at home to Kent State) and Louisville (which would have lost to Rutgers) would be excluded, as would potential non-BCS party crashers like Boise State, Louisiana Tech and the winner of the MAC.

Talk about a nightmare. And here's another potential scenario that should keep you awake at night: If the Tigers beat the Crimson Tide, doesn't that leave the potential for another LSU-Alabama rematch in the national championship game?